Simpson Strong-Tie Strong-Drive Hex Head Structural Screw Simpson Strong-Drive structural wood screws. High-strength alternative to through-bolting and traditional lag screws. Bold thread design provides superior holding power. Patented 4CUT tip to ensure fast start and reduced installation torque, eliminating pre-drilling in most applications. Large head provides maximum bearing area. Double-barrier coating makes screw suitable for exterior and preservative-treated wood applications. Bit included in package. Screw diameter 0.195 with large hex head drive. Thread Diameter 0.195 , Length 4 In., Head Type Large Hex Washer, Finish Double-Barrier Coating, Material Stainless Steel, Shank Diameter 0.195 In., Drive Type 5/16 In. Hex, Pkg Qty 50, Package Type Box WARNING! Cancer www.P65Warnings.ca.gov